Supporting Information for “Anomalous complex electrical conductivity of a graphitic black schist from the Himalayas of central Nepal” Jana H. Börner 1 , Frédéric Girault 2 , Mukunda Bhattarai 3 , Lok Bijaya Adhikari 3 , Damien Deldicque 4 , Frédéric Perrier 2 and Klaus Spitzer 1 1 Institute of Geophysics and Geoinformatics, TU Bergakademie Freiberg, Germany 2 Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Univ. Paris Diderot, CNRS, Paris, France 3 National Seismological Centre, Department of Mines and Geology, Lainchaur, Kathmandu, Nepal 4 Laboratoire de Géologie de l’ENS - PSL Research University - UMR 8538 CNRS, Paris, France Contents S1 Measuring cell Figure S1: Measuring cell used for the experiments. S2 Double Cole-Cole modeling Figure S2: Double Cole-Cole modelling for three samples. Table S1: Double Cole-Cole model parameters. S3 Black schist - quartz sand mixtures Figure S3: Complex conductivity of the black schist - quartz mixtures. S4 Confirmation of black schist characteristics by means of SEM images Figure S4: SEM images of black schist and augen gneiss confirm the implications on polarization mechanisms and rock texture derived from complex conductivity measurements. S5 Impact of CO 2 on complex conductivity of black schist and augen gneiss Figure S5: Impact of exposure to CO 2 at 5 MPa and 30°C on the conductivity of crushed black schist, crushed augen gneiss and quartz sand. S6 Demonstration of the effect of complex conductivity on MT data and inversion S7 Data Corresponding author: Jana H. Börner, jana.boerner@geophysik.tu-freiberg.de –1–